14 DAY TRIAL // A molecule containing a radioactive form of carbon can be used to locate aromatase – an enzyme responsible for the production of estrogen in the human brain, concluded a study carried out by the United States Department of Energy's (DOE) Brookhaven National Laboratory.
Furthermore, it seems that the areas of the brain where aromatase if concentrated could be unique to humans.
Anat Biegon, a Brookhaven neurobiologist, explained that “the original purpose of the study was to expand our use of this radiotracer, N-methyl-11C vorozole.
“Proving that a radiotracer like vorozole can be used for brain-imaging studies in humans would be a gateway to new research on estrogen in the brain.
“You cannot look at these brain pathways in living humans in any other way.”
At the study took part six young, nonsmoking, healthy individuals – three men and three women, who underwent Positron Emission Tomography (PET).
Before the scans, all six subjects received a shot with a radiolabeled form of vorozole, synthesized and purified by Brookhaven radiochemists.
The men were given an aromatase inhibitor and underwent a second scan, which proved that the inhibitor lowered the radioactive vorozole concentrations, and decreased the availability of aromatase.
However, the real surprise was when the researchers looked at the anatomical distribution of aromatase in the brain, and found the highest levels in the thalamus and the medulla.
In previous animal studies, aromatase was nowhere near these areas, being concentrated in smaller regions like the amygdala and the preoptic areas.
This study was the first to prove that vorozole is a useful radiotracer for studying estrogen-producing hotspots in the human brain.
Biegon said that it all “started as a simple tool development study and now it's turned out to be much more interesting than that.
“The question that's raised is what is aromatase doing in these particular brain regions?”
Answering it is the next step for Biegon and her colleagues, so they have already begun a larger study, on a group of 30 people.
Once brain aromatase in healthy subjects has no more secrets, the researchers should move on to subjects with specific conditions, and study the role that the estrogen in the brain has, when it comes to unusual aggression, breast cancer or Alzheimer's disease.
This research is published in the November issue of Synapse.